Edward’s Aquifer Ground-water Flow Model Texas Ground Water 2004 November 19, 2004 George B. Ozuna.

Edward’s Aquifer Ground-water Flow Model

Texas Ground Water 2004November 19, 2004George B. Ozuna

Edwards Aquifer Model

• In cooperation with: Edwards Aquifer Authority Department of Defense USGS

• Richard Lindgren, USGS• Sue Horvorka and Alan Dutton, BEG• Scott Painter, SwRI• Steve Worthington, Consultant


• Uniform ¼-mi grid • 370 rows; 700 columns; 259,000 cells• One layer• Grid alignment:

Major faults and flow near Comal and San Marcos Springs

Structure

• Aquifer top elevation• Aquifer bottom elevation• Faults

Provided by BEG – Sue Horvorka

Faults

• Simulated using Horizontal Flow Barrier Package

• Model inputs: fault location hydraulic characteristic (C)

o hydraulic conductance termo Assumption: hydraulic characteristic (C) is a

function of fault displacement inversely proportional

Las Moras Springs

Leona Springs

San Antonio & San Pedro Springs

Comal Springs

San Marcos Springs

Fault

Simulated Faults And Springs

General-head boundary

No-flow boundary – saline water line

General-head boundary

No-flow

Colorado River – Head-dependent flux boundary

No- flow

Recharge zone

Model Boundary Conditions

Hydraulic Conductivity

Provided by Southwest Research – Scott Painter

Conduits

Provided by EAA Consultant - Steve Worthington

Hydraulic Properties

Simulated Recharge Zones

Recharge Zone - Stream Channels

Pumpage – by use

Provided by BEG – Alan Dutton

Pumpage – by rate

Provided by BEG – Alan Dutton

Steady-State Calibration

• Calibration period: 1939 – 1946• Pre-1950’s drought, minimal irrigation

development• Near-normal precipitation• San Antonio precipitation: normal 1961-90 30.98 in/yr average 1939-46 30.47 in/yr

Steady-State Target Wells

144 wells

Steady-State Calibration

Transient Calibration

• Calibration period: 1947 – 2000• Calibration targets:

Long-term record wellso County Index wellso match hydrographs

Selected time periodso periods of above- and below-normal precipitationo match hydraulic heads for a set of wells

Transient Calibration

• Selected time periods Below-normal precipitation

o 1952-57 May thru November 1956 175 wells

Above-normal precipitationo 1973-77

November 1974 thru July 1975 172 wells

Transient Target Wells

Drought Conditions, 175 Wells, May – November 1956

Transient Target Wells

Wet Conditions, 172 Wells, November 1974 – July 1975

Transient Target Springs

• 5 springs simulated: San Marcos Comal Leona San Pedro* San Antonio*

*Based on relation with Bexar index well

Uvalde Index Well

Medina Index Well

Comal Well

San Marcos Well

Transient ResultsWater-Level Hydrographs

Bexar Index Well


Uvalde_index(south-central Uvalde County)

810

820

830

840

850

860

870

880

890

900

910

920

930

1/1/1947

1/1/1949

1/1/1951

1/1/1953

1/1/1955

1/1/1957

1/1/1959

1/1/1961

1/1/1963

1/1/1965

1/1/1967

1/1/1969

1/1/1971

1/1/1973

1/1/1975

1/1/1977

1/1/1979

1/1/1981

1/1/1983

1/1/1985

1/1/1987

1/1/1989

1/1/1991

1/1/1993

1/1/1995

1/1/1997

1/1/1999

1/1/2001

Date

Ele

va

tio

n

Measured

Simulated


Medina_6841301(east-central Medina County)

600610620630640650660670680690700710720730740750760770780

1/1/1950

1/1/1952

1/1/1954

1/1/1956

1/1/1958

1/1/1960

1/1/1962

1/1/1964

1/1/1966

1/1/1968

1/1/1970

1/1/1972

1/1/1974

1/1/1976

1/1/1978

1/1/1980

1/1/1982

1/1/1984

1/1/1986

1/1/1988

1/1/1990

1/1/1992

1/1/1994

1/1/1996

1/1/1998

1/1/2000

Date

Ele

va

tio

n

Measured

Simulated


Bexar_index(central Bexar County)

600

610

620

630

640

650

660

670

680

690

700

710

1/1/1947

1/1/1949

1/1/1951

1/1/1953

1/1/1955

1/1/1957

1/1/1959

1/1/1961

1/1/1963

1/1/1965

1/1/1967

1/1/1969

1/1/1971

1/1/1973

1/1/1975

1/1/1977

1/1/1979

1/1/1981

1/1/1983

1/1/1985

1/1/1987

1/1/1989

1/1/1991

1/1/1993

1/1/1995

1/1/1997

1/1/1999

1/1/2001

Date

Ele

va

tio

n

Measured

Simulated


Comal_6823701(central Comal County)

600

610

620

630

640

650

660

670

680

690

1/1/1947

1/1/1949

1/1/1951

1/1/1953

1/1/1955

1/1/1957

1/1/1959

1/1/1961

1/1/1963

1/1/1965

1/1/1967

1/1/1969

1/1/1971

1/1/1973

1/1/1975

1/1/1977

1/1/1979

1/1/1981

1/1/1983

1/1/1985

1/1/1987

1/1/1989

1/1/1991

1/1/1993

1/1/1995

Date

Ele

va

tio

n

Measured

Simulated


Hays_5858101(eastern Hays County)

530540550560570580590600610620630640650660670

1/1/1947

1/1/1949

1/1/1951

1/1/1953

1/1/1955

1/1/1957

1/1/1959

1/1/1961

1/1/1963

1/1/1965

1/1/1967

1/1/1969

1/1/1971

1/1/1973

1/1/1975

1/1/1977

1/1/1979

1/1/1981

1/1/1983

1/1/1985

1/1/1987

1/1/1989

1/1/1991

1/1/1993

1/1/1995

1/1/1997

1/1/1999

1/1/2001

Date

Ele

va

tio

n

Measured

Simulated

Leona Springs

Comal Springs

San Marcos Springs

Transient ResultsSpringflow Hydrographs


Comal Springs

0

5,000,000

10,000,000

15,000,000

20,000,000

25,000,000

30,000,000

35,000,000

40,000,000

45,000,000

50,000,000

1/1/1947

1/1/1949

1/1/1951

1/1/1953

1/1/1955

1/1/1957

1/1/1959

1/1/1961

1/1/1963

1/1/1965

1/1/1967

1/1/1969

1/1/1971

1/1/1973

1/1/1975

1/1/1977

1/1/1979

1/1/1981

1/1/1983

1/1/1985

1/1/1987

1/1/1989

1/1/1991

1/1/1993

1/1/1995

1/1/1997

1/1/1999

1/1/2001

Date

Flo

w in

cu

bic

fe

et

pe

r d

ay

Measured

Simulated


San Marcos Springs

0

5,000,000

10,000,000

15,000,000

20,000,000

25,000,000

30,000,000

35,000,000

40,000,000

45,000,000

1/1/1947

1/1/1949

1/1/1951

1/1/1953

1/1/1955

1/1/1957

1/1/1959

1/1/1961

1/1/1963

1/1/1965

1/1/1967

1/1/1969

1/1/1971

1/1/1973

1/1/1975

1/1/1977

1/1/1979

1/1/1981

1/1/1983

1/1/1985

1/1/1987

1/1/1989

1/1/1991

1/1/1993

1/1/1995

1/1/1997

1/1/1999

1/1/2001

Date

Flo

w in

cu

bic

fe

et

pe

r d

ay

Measured

Simulated


Leona Springs

0

2,000,000

4,000,000

6,000,000

8,000,000

10,000,000

12,000,000

1/1/1947

1/1/1949

1/1/1951

1/1/1953

1/1/1955

1/1/1957

1/1/1959

1/1/1961

1/1/1963

1/1/1965

1/1/1967

1/1/1969

1/1/1971

1/1/1973

1/1/1975

1/1/1977

1/1/1979

1/1/1981

1/1/1983

1/1/1985

1/1/1987

1/1/1989

1/1/1991

1/1/1993

1/1/1995

1/1/1997

1/1/1999

1/1/2001

Date

Flo

w in

cu

bic

fe

et

pe

r d

ay

Measured

Simulated


• Model Inputs Structure Boundary Conditions Hydraulic Properties Stresses

• Model Calibration Targets Steady-State Results Transient Results

Edward’s Aquifer Ground-water Flow Model Texas Ground Water 2004 November 19, 2004 George B. Ozuna.

Documents

alan duttonpumpage

major faults

function of fault displacement

begscott painter

usgssue horvorka

swristeve worthington

calibration targets

sue horvorkafaultssimulated